As a user it can be extremely frustrating if you’re using an application and you have to wait an extended period of time while the application updates.

Sadly this was pretty common when the app store was new. The devices were slower, the networks were slower, and many apps weren’t using multi-threading in places they probably should have. I remember becoming frustrated many times using an RSS reader, waiting for the article list to update, and then waiting again for the article to display.

Multithreaded programming with GCD can still be intimidating. I’ve found a great step-by-step guide which breaks things down into a step by step guide explaining things fully every step of the process of downloading data asynchronously and updating in real time.